Various types of fuel filters have been proposed to extract soluble and non-soluble water in fuel. Fuel, especially diesel fuel, typically has a certain quantity of water in soluble form that may hinder performance of an engine. Fuel also usually has a certain quantity of water in non-soluble form, which tends to be created during transport and storage of the fuel.
A conventional diesel fuel filter typically includes a fine paper that separates water from fuel by coalescence so that the fuel may pass downstream to the engine with little to no water entrained therein. Over time, however, water accumulates on the surface of the fuel filter and the level of the accumulated water rises and clogs an ever increasing surface area of the filter. The rising level of accumulated water thereby impedes fuel flow therethrough and creates a pressure drop thereacross. This blockage and pressure drop tends to slow down the passage of fuel through the filter and can lead to gradual or sudden releases of water from the filter to the engine.
Therefore, a conventional diesel fuel filter must be mounted in an accessible location on a vehicle for servicing by a mechanic. After accessing the fuel filter, the mechanic removes plugs or opens valves thereof, and then pumps water out of a drain hole of the filter while allowing make up air to enter the filter through a vent hole thereof. Finally, the mechanic refills the filter with fuel, and replaces the plugs or closes the valves. Unfortunately, such a conventional diesel fuel filter cannot be located within a relatively inaccessible location within a fuel tank because of the need for a mechanic to easily access, drain, and refill the filter.